Neutral red serves as a pH indicator in MacConkey agar, which is a selective and differential culture medium for gram-negative bacteria. It helps to distinguish lactose-fermenting bacteria, such as Escherichia coli, from non-lactose fermenters. When lactose is fermented, acidic byproducts lower the pH, causing the neutral red to turn pink, indicating the presence of lactose fermenters. In contrast, non-lactose fermenters remain colorless or take on the color of the medium.
MacConkey agar contains bile salts, lactose, peptone. crystal violet dye, and neutral red dye. The agar appears a medium pink with a copper undertone.
MacConkey agar is a selective medium designed to grow Gram negavite bacteria and stain them for lactose fermentation. It contains bile salts[to inhibit most Gram negative bacteria and some species of Staphlococcus], crystal violet dye, neutral red dye ,lactose and peptone. It was first developed by Alfred Theodore MacConkey. It is used to distinguish between lactose fermenting bacteria and non lactose fermenting bacteria. By utilising the lactose available in the medium, Lac+ bacteria such as Escherichia coli, Enterobacter and Klebsiella will produce acid, which lowers the pH of the agar below 6.8 and results in the appearance of red/pink colonies. Non-Lactose fermenting bacteria such as Salmonella, Proteus species and Shigella cannot utilize lactose, and will use peptone instead. This forms ammonia, which raises the pH of the agar, and leads to the formation of white/colorless colonies
Lac+ bacteria is acid base color indicator that lowers the pH of the MacConkey agar. The MacConkey agar contains neutral red dye, lactose, peptone, and crystal violet dye.
red algae Agar agar is a malay term meaning red algae. This algae which agar is extracted lives in the ocean around Malaysia
It's a differential agar used to differentiate between lactose fermenters and non-lactose fermenteing bacteria. Chemical composition of Mac Conkey agar Peptone 20.0g Trehalose 10.0g Bile salts(Difco) 1.5g Sodium Cloride 5.0 Neutral Red 0.05g Crystal Violet 0.001 Agar 15.0g Distelled water 1.0 liter pH: 7.4±0.2 (25 °C)
Neutral red serves as a pH indicator in MacConkey agar, which is a selective and differential culture medium for gram-negative bacteria. It helps to distinguish lactose-fermenting bacteria, such as Escherichia coli, from non-lactose fermenters. When lactose is fermented, acidic byproducts lower the pH, causing the neutral red to turn pink, indicating the presence of lactose fermenters. In contrast, non-lactose fermenters remain colorless or take on the color of the medium.
MacConkey agar contains bile salts, lactose, peptone. crystal violet dye, and neutral red dye. The agar appears a medium pink with a copper undertone.
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MacConkey agar is a selective medium designed to grow Gram negavite bacteria and stain them for lactose fermentation. It contains bile salts[to inhibit most Gram negative bacteria and some species of Staphlococcus], crystal violet dye, neutral red dye ,lactose and peptone. It was first developed by Alfred Theodore MacConkey. It is used to distinguish between lactose fermenting bacteria and non lactose fermenting bacteria. By utilising the lactose available in the medium, Lac+ bacteria such as Escherichia coli, Enterobacter and Klebsiella will produce acid, which lowers the pH of the agar below 6.8 and results in the appearance of red/pink colonies. Non-Lactose fermenting bacteria such as Salmonella, Proteus species and Shigella cannot utilize lactose, and will use peptone instead. This forms ammonia, which raises the pH of the agar, and leads to the formation of white/colorless colonies
Lac+ bacteria is acid base color indicator that lowers the pH of the MacConkey agar. The MacConkey agar contains neutral red dye, lactose, peptone, and crystal violet dye.
red algae Agar agar is a malay term meaning red algae. This algae which agar is extracted lives in the ocean around Malaysia
If neutral red were replaced with phenol red in MacConkey agar, the pH indicator's response to acid production would change. Neutral red typically turns red in the presence of acid, indicating lactose fermentation by coliform bacteria, while phenol red changes from red to yellow in acidic conditions. This alteration could lead to misinterpretation of lactose fermenters, as the color changes may not provide the same level of differentiation or clarity for identifying lactose-positive colonies. Thus, the overall effectiveness of the medium for isolating and identifying enteric bacteria could be compromised.
Agar comes from Red Algae (primarily the Gracilaria genus).It mainly is produed from the red algae Gracilaria lichenoides.This algae is harvested along the western coast of the United States and in parts of Asia. To extract the agar the Algae is boiled, cooled, purified and then dried. The agar is then make into blocks, flakes, or granules.("Agar agar" is usually abbreviated as "agar".)
Aerobacter aerogenes produces a pink color on EMB agar due to its ability to ferment lactose, which results in the production of acid byproducts. This acidic environment causes the neutral red pH indicator in the agar to turn pink. This characteristic color change helps differentiate Aerobacter aerogenes from other bacterial species on the agar plate.
marine red algae
Red algae cell walls contain agar. while green algae cell walls contain cellulose Answer 2 Agar is a chemical obtained from walls of certain red marine algae .It is not Algae itself .